Pure ammonia engine system and control method thereof

Abstract

The invention provides a pure ammonia engine system and a control method thereof. The pure ammonia engine system comprises a cylinder block; the air cylinder cover covers the air cylinder body, and a combustion chamber is formed between the air cylinder cover and the air cylinder body; the glow plug comprises a heating body which extends into the combustion chamber from the center of the cylinder cover; the controller is configured to regulate and control the temperature of the hot surface of the heating body based on the operation condition of the pure ammonia engine system; the liquid ammonia ejector is inserted into the combustion chamber from the cylinder cover and is positioned on one side of the glow plug; the spark plug is inserted into the combustion chamber from the cylinder cover and is positioned on the other side, radially opposite to the liquid ammonia ejector, of the glow plug; a plurality of spraying hole sets are formed in the side, facing the heating body, of the end, extending into the combustion chamber, of the liquid ammonia ejector, so that part of liquid ammonia mist sprayed out of the liquid ammonia ejector is filled around the heating body to be ignited by a sparking plug.

Description

Technical Field

[0001] The present disclosure relates to the technical field of large-bore marine engines fueled by ammonia, and more particularly, to a pure ammonia engine system and a control method thereof. Background Art

[0002] The development and application of new, efficient and clean alternative fuels have become a research hotspot in the field of engines. As a zero-carbon fuel, ammonia fuel has the advantages of high energy density, high octane number and easy storage and transportation, making it have good potential as an alternative fuel for engines. In recent years, the technical route of direct injection of liquid ammonia into the cylinder for combustion has received more attention. However, the large latent heat of vaporization of liquid ammonia causes a large amount of heat to be absorbed after liquid ammonia enters the engine cylinder, resulting in a decrease in the cylinder temperature. At the same time, due to the slow combustion speed of liquid ammonia, the engine has low combustion efficiency and poor combustion stability, and a large amount of unburned ammonia is generated in the cylinder, which is difficult to be purified by the existing aftertreatment system.

[0003] Currently, the main solution to the above problems is to use high-reactivity fuels such as diesel for ignition. However, on the one hand, an additional fuel system needs to be arranged, which increases the system complexity and cost. On the other hand, this is also not conducive to the realization of the zero-carbon goal. Summary of the Invention

[0004] To solve at least one of the technical problems in the prior art, an embodiment of the present disclosure provides a pure ammonia engine system and a control method thereof, and the pure ammonia engine system can stably ignite under all operating conditions.

[0005] An embodiment of the present disclosure provides a pure ammonia engine system, including: a cylinder block; a cylinder head covering above the cylinder block, a combustion chamber being formed between the cylinder head and the cylinder block; an electric glow plug including a heating element extending into the interior of the combustion chamber at the center of the cylinder head; a controller configured to regulate the temperature of the hot surface of the heating element based on the operating conditions of the pure ammonia engine system; a liquid ammonia injector inserted into the combustion chamber from the cylinder head and located on one side of the electric glow plug; a spark plug inserted into the combustion chamber from the cylinder head and located on the other side of the electric glow plug radially opposite to the liquid ammonia injector; wherein, a plurality of spray hole groups are provided on one end face of the liquid ammonia injector extending into the interior of the combustion chamber facing one side of the heating element, so that a part of the liquid ammonia spray ejected by the liquid ammonia injector fills around the heating element to be ignited by the spark plug.

[0006] According to some embodiments of the present disclosure, the plurality of the above-mentioned spray hole groups include: a first spray hole group arranged facing the above-mentioned heating element, such that the ammonia spray ejected from the first spray hole group impacts on the hot surface of the heating element, so as to accelerate the fragmentation and evaporation of the ammonia spray ejected from the first spray hole group and mix with the air in the combustion chamber to form a combustible mixture, which is thus ignited by the spark plug; two second spray hole groups symmetrically distributed on both sides of the first spray hole group perpendicular to the plane where the axis direction of the ammonia injector is located, such that the ammonia sprays ejected from the two second spray hole groups fill the periphery of the heating element.

[0007] According to some embodiments of the present disclosure, the above-mentioned first spray hole group and each of the above-mentioned second spray hole groups each include: two spray holes arranged at intervals along the axis of the ammonia injector.

[0008] According to some embodiments of the present disclosure, the axis of the above-mentioned glow plug coincides with the axis of the combustion chamber, and the axis of the ammonia injector is inclined with respect to the axis of the glow plug, such that the ammonia spray ejected from the first spray hole group directly impacts on the hot surface of the heating element.

[0009] According to some embodiments of the present disclosure, the axis of the above-mentioned spark plug is inclined with respect to the axis of the glow plug to ignite the ammonia spray around the heating element.

[0010] According to some embodiments of the present disclosure, the pure ammonia engine system further includes: an ammonia supply mechanism configured to supply ammonia; an ammonia supercharger connected to the ammonia supply mechanism, the ammonia supercharger being configured to supercharge the ammonia; an ammonia common rail connected between the ammonia supercharger and the ammonia injector, the ammonia common rail being configured to regulate the pressure of the ammonia ejected from the plurality of the above-mentioned spray hole groups.

[0011] According to some embodiments of another aspect of the present disclosure, there is provided a control method for a pure ammonia engine system, which is applied to the above-mentioned pure ammonia engine system. The control method includes: obtaining the operating condition of the pure ammonia engine system; the glow plug adjusts the temperature of the hot surface of the heating element in response to the operating condition of the pure ammonia engine system to provide different temperature environments for the spark plug to ignite the ammonia spray inside the combustion chamber.

[0012] According to some embodiments of the present disclosure, the above operating conditions are divided into a cold start condition, a small load condition, a medium load condition, and a large load condition according to the output torque of the above pure ammonia engine system from low to high, and the temperature inside the above combustion chamber increases with the increase of the above output torque; when the above pure ammonia engine system is in the above cold start condition, control the above electric heating plug to work at full load; as the above pure ammonia engine system runs to the above small load condition and the above medium load condition, control the temperature of the above hot surface to gradually decrease; as the above pure ammonia engine system runs to the above large load condition, control the above electric heating plug to stop working.

[0013] According to some embodiments of the present disclosure, when the above pure ammonia engine system is in the above cold start condition, the temperature of the above hot surface is 300°C to 400°C; when the above pure ammonia engine system runs to the above small load condition and the above medium load condition, the temperature of the above hot surface is 100°C to 200°C.

[0014] According to some embodiments of the present disclosure, based on the rotational speed value of the rotational speed sensor connected to the crankshaft of the above pure ammonia engine system and the displacement amount of the accelerator pedal connected to the above pure ammonia engine system, determine the above output torque of the above pure ammonia engine system, so as to determine the operating condition of the above pure ammonia engine system.

[0015] For the pure ammonia engine system and its control method according to the embodiments of the present disclosure, the cylinder head is provided above the cylinder block, a combustion chamber is formed between the cylinder head and the cylinder block, the electric heating plug includes a heating element extending into the combustion chamber inside the center of the cylinder head, the controller is configured to regulate the temperature of the hot surface of the heating element based on the operating condition of the pure ammonia engine system, so as to change the temperature inside the combustion chamber, the liquid ammonia injector is inserted into the combustion chamber from the cylinder head and is located on one side of the electric heating plug, the spark plug is inserted into the combustion chamber from the cylinder head and is located on the other side of the electric heating plug radially opposite to the liquid ammonia injector, and a plurality of spray hole groups are provided on the end face of the liquid ammonia injector extending into the combustion chamber facing one side of the heating element, so that a part of the liquid ammonia spray ejected by the liquid ammonia injector fills the surrounding of the heating element, making it easier to be ignited by the spark plug, improving the problems of low combustion efficiency and poor combustion stability caused by the large latent heat of vaporization of liquid ammonia and slow combustion speed, and reducing the unburned liquid ammonia in the cylinder block, so that the pure ammonia engine system can stably ignite under all operating conditions. Description of the Drawings

[0016] Figure 1 is a cross-sectional view of a pure ammonia engine system according to a schematic embodiment of the present disclosure;

[0017] Figure 2 is Figure 1 a partial enlarged view of part A in

[0018] Figure 3 is a bottom view corresponding to a sectional view of a pure ammonia engine system according to an exemplary embodiment of the present disclosure;

[0019] Figure 4 is a flowchart of a control method for a pure ammonia engine system according to an exemplary embodiment of the present disclosure.

[0020] In the drawings, the meanings of the reference numerals are as follows:

[0021] 1. Cylinder block;

[0022] 2. Cylinder head;

[0023] 3. Combustion chamber;

[0024] 4. Glow plug;

[0025] 41. Heating element;

[0026] 5. Controller;

[0027] 6. Liquid ammonia injector;

[0028] 600. Spray hole group;

[0029] 610. First spray hole group;

[0030] 620. Second spray hole group;

[0031] 61. Spray hole;

[0032] 7. Spark plug;

[0033] 100. Liquid ammonia supply mechanism;

[0034] 8. Ammonia gas source;

[0035] 9. Ammonia gas liquefaction device;

[0036] 10. Instantaneous fuel consumption meter;

[0037] 11. Liquid ammonia boosting device;

[0038] 12. Liquid ammonia common rail;

[0039] 13. Piston;

[0040] 14. Intake passage;

[0041] 15. Exhaust passage;

[0042] 16. First liquid ammonia spray beam;

[0043] 17. Second liquid ammonia spray beam. Detailed implementation manners

[0044] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the following detailed description, for the sake of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. However, obviously, one or more embodiments can also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily obscuring the concepts of the present disclosure.

[0045] The terms used herein are merely for describing specific embodiments and are not intended to limit the present disclosure. The terms “including,” “comprising,” etc. used herein indicate the presence of the described features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0046] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those of ordinary skill in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0047] In cases where expressions such as “at least one of A, B, and C, etc.” are used, generally, it should be interpreted according to the meaning commonly understood by those of ordinary skill in the art (for example, “a system having at least one of A, B, and C” should include, but not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.). In cases where expressions such as “at least one of A, B, or C, etc.” are used, generally, it should be interpreted according to the meaning commonly understood by those of ordinary skill in the art (for example, “a system having at least one of A, B, or C” should include, but not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0048] To solve the problems of low combustion efficiency and poor combustion stability caused by the large latent heat of vaporization of liquid ammonia and slow combustion speed, according to the inventive concept of one aspect of the present disclosure, a pure ammonia engine system and its control method are provided. The cylinder head is disposed above the cylinder block, and a combustion chamber is formed between the cylinder head and the cylinder block. The glow plug includes a heating element extending into the interior of the combustion chamber at the center of the cylinder head. The controller is configured to regulate the temperature of the hot surface of the heating element based on the operating conditions of the pure ammonia engine system, thereby changing the temperature inside the combustion chamber. The liquid ammonia injector is inserted into the combustion chamber from the cylinder head and is located on one side of the glow plug. The spark plug is inserted into the combustion chamber from the cylinder head and is located on the other side of the glow plug that is radially opposite to the liquid ammonia injector. A plurality of spray hole groups are provided on one side of the end face of the liquid ammonia injector extending into the interior of the combustion chamber facing the heating element, so that part of the liquid ammonia spray ejected by the liquid ammonia injector fills the surrounding of the heating element, making it easier to be ignited by the spark plug, improving the problems of low combustion efficiency and poor combustion stability caused by the large latent heat of vaporization of liquid ammonia and slow combustion speed, and reducing the unburned liquid ammonia in the cylinder block. The pure ammonia engine system can stably ignite under all operating conditions.

[0049] Figure 1 It is a cross-sectional view of a pure ammonia engine system according to an exemplary embodiment of the present disclosure.

[0050] A pure ammonia engine system provided according to an embodiment of the present disclosure, as Figure 1 shown, includes a cylinder block 1, a cylinder head 2, a glow plug 4, a controller 5, a liquid ammonia injector 6, and a spark plug 7. The cylinder head 2 is disposed above the cylinder block 1, and a combustion chamber 3 is formed between the cylinder head 2 and the cylinder block 1. The glow plug 4 includes a heating element 41 extending into the interior of the combustion chamber 3 at the center of the cylinder head 2. The controller 5 is configured to regulate the temperature of the hot surface of the heating element 41 based on the operating conditions of the pure ammonia engine system. The liquid ammonia injector 6 is inserted into the combustion chamber 3 from the cylinder head 2 and is located on one side of the glow plug 4. The spark plug 7 is inserted into the combustion chamber 3 from the cylinder head 2 and is located on the other side of the glow plug 4 that is radially opposite to the liquid ammonia injector 6. A plurality of spray hole groups are provided on one side of the end face of the liquid ammonia injector 6 extending into the interior of the combustion chamber 3 facing the heating element 41, so that part of the liquid ammonia spray ejected by the liquid ammonia injector 6 fills the surrounding of the heating element 41 to be ignited by the spark plug 7.

[0051] According to an embodiment of the present disclosure, a piston 13 is slidably installed in the cylinder block 1, and the cylinder head 2, the cylinder block 1, and the piston 13 enclose the combustion chamber 3.

[0052] According to an embodiment of the present disclosure, an intake passage 14 and an exhaust passage 15 are further provided on the cylinder head 2, and the controller 5 is further configured to control the opening and closing times of the intake passage 14 and the exhaust passage 15 to complete the intake process and the exhaust process of the combustion chamber 3.

[0053] According to an embodiment of the present disclosure, the controller 5 is configured to regulate the temperature of the hot surface of the heating element 41 based on the operating conditions of the pure ammonia engine system. When the pure ammonia engine system is in a cold start condition, the controller 5 controls the hot surface of the heating element 41 to heat up, so that the surrounding of the hot surface of the heating element 41 is a high-temperature region, thereby increasing the temperature inside the combustion chamber 3. When the pure ammonia engine system is in a small load condition and a medium load condition, at this time, the thermodynamic conditions inside the combustion chamber 3 are improved, and the controller 5 controls the hot surface of the heating element 41 to cool down, which not only ensures the stable combustion of the liquid ammonia spray inside the combustion chamber 3, but also improves the energy utilization efficiency of the pure ammonia engine system. When the pure ammonia engine system is in a large load condition, at this time, the thermodynamic conditions inside the combustion chamber 3 have been improved to ensure the stable combustion of the liquid ammonia spray inside the combustion chamber 3, and the controller 5 controls the glow plug 4 to stop working, improving the energy utilization efficiency of the pure ammonia engine system.

[0054] According to an embodiment of the present disclosure, the cylinder head 2 is disposed above the cylinder block 1, a combustion chamber 3 is formed between the cylinder head 2 and the cylinder block 1, the glow plug 4 includes a heating element 41 extending into the combustion chamber 3 at the center of the cylinder head 2, and the controller 5 is configured to regulate the temperature of the hot surface of the heating element 41 based on the operating conditions of the pure ammonia engine system, thereby changing the temperature inside the combustion chamber 3. The liquid ammonia injector 6 is inserted into the combustion chamber 3 from the cylinder head 2 and is located on one side of the glow plug 4, and the spark plug 7 is inserted into the combustion chamber 3 from the cylinder head 2 and is located on the other side of the glow plug 4 radially opposite to the liquid ammonia injector 6. A plurality of spray hole groups are provided on one side of the end of the liquid ammonia injector 6 extending into the combustion chamber 3 facing the heating element 41, so that part of the liquid ammonia spray ejected from the liquid ammonia injector 6 fills the surrounding of the heating element 41, making it easier to be ignited by the spark plug 7, while improving the problems of low combustion efficiency and poor combustion stability caused by the large latent heat of vaporization and slow combustion speed of liquid ammonia, and reducing the unburned liquid ammonia in the cylinder block 1.

[0055] According to an embodiment of the present disclosure, the glow plug 4 for auxiliary ignition not only has a simple structure, requires less modification to the existing engine system, but also has a relatively low cost. More importantly, as an auxiliary ignition mechanism, the glow plug 4 has a much larger hot surface area and ignition energy than traditional spark plugs and other methods. Therefore, applying the glow plug 4 for auxiliary ignition to the pure ammonia engine system helps the pure ammonia engine system to stably ignite under all operating conditions.

[0056] Figure 2 is Figure 1 The partial enlarged view at position A in Figure 2 shown in is the side of the end of the liquid ammonia injector 6 extending into the combustion chamber 3 facing the heating element 41.

[0057] According to an embodiment of the present disclosure, as shown in Figure 2As shown, a plurality of nozzle groups 600 include a first nozzle group 610 and two second nozzle groups 620. The first nozzle group 610 is arranged facing the heating element 41, such that the ammonia spray ejected from the first nozzle group 610 impacts on the hot surface of the heating element 41, so as to accelerate the breakup and evaporation of the ammonia spray ejected from the first nozzle group 610 and mix with the air in the combustion chamber 3 to form a combustible mixture, which is thus ignited by the spark plug 7. The two second nozzle groups 620 are symmetrically distributed on both sides of the first nozzle group 610 with respect to the plane perpendicular to the axis direction of the ammonia injector 6, such that the ammonia spray ejected from the two second nozzle groups 620 fills the periphery of the heating element 41.

[0058] According to an embodiment of the present disclosure, the glow plug 4 is located at the center of the cylinder head 2, and the ammonia injector 6 is located on one side of the glow plug 4. Since the ammonia injector 6 is side-mounted, the ammonia spray ejected from the nozzles of the ammonia injector 6 extending into the combustion chamber 3 and close to the wall surface of the cylinder block 1 will cause a large amount of ammonia spray to hit the wall, thus affecting normal combustion. Therefore, the nozzles of the ammonia injector 6 close to the wall surface of the cylinder block 1 are cancelled, and a plurality of nozzle groups 600 are formed on the side facing the heating element 41 at one end of the ammonia injector 6 extending into the combustion chamber 3, so as to ensure that the injection pulse width will not increase significantly under the same ammonia injection volume. Moreover, the ammonia spray beam ejected from the first nozzle group 610 impacts on the hot surface of the heating element 41, accelerating the breakup and evaporation of the ammonia spray ejected from the first nozzle group 610 and mixing with the air in the combustion chamber 3 to form a combustible mixture, which is conducive to stable ignition and combustion after being ignited by the spark plug 7.

[0059] According to an embodiment of the present disclosure, the ammonia spray ejected from the two second nozzle groups 620 diffuses in the high-temperature region near the hot surface of the heating element 41, such that the ammonia spray can be stably ignited and combusted after the spark plug 7 ignites, improving the problems of low ammonia combustion efficiency and unstable combustion caused by the slow ammonia combustion propagation speed.

[0060] According to an embodiment of the present disclosure, the first nozzle group 610 and each second nozzle group 620 each include two nozzles 61, and the two nozzles 61 are arranged at intervals along the axis of the ammonia injector 6.

[0061] According to an embodiment of the present disclosure, the three nozzles 61 of the first nozzle group 610 and the two second nozzle groups 620 close to the cylinder head 2 are located on a first circumference with the center of the circle falling on the axis of the ammonia injector 6, and the three nozzles 61 of the first nozzle group 610 and the two second nozzle groups 620 away from the cylinder head 2 are located on a second circumference with the center of the circle falling on the axis of the ammonia injector 6, and the first circumference and the second circumference are arranged at intervals.

[0062] Figure 3 is a bottom view corresponding to a cross-sectional view of a pure ammonia engine system according to an exemplary embodiment of the present disclosure.

[0063] According to an embodiment of the present disclosure, as Figure 3 shown, among the three injection holes 61 where the first injection hole group 610 and the two second injection hole groups 620 are away from the cylinder head 2, the first liquid ammonia spray oil beam 16 ejected from the injection hole 61 belonging to the first injection hole group 610 impacts on the hot surface of the heating element 41, accelerating the fragmentation and evaporation of the liquid ammonia spray ejected from the first injection hole group 610 and mixing with the air in the combustion chamber 3 to form a combustible mixture. The second liquid ammonia spray oil beam 17 ejected from the injection hole 61 belonging to the two second injection hole groups 620 diffuses in the high-temperature region near the hot surface of the heating element 41, enabling the liquid ammonia spray to stably ignite and burn after the spark plug 7 ignites.

[0064] In a schematic embodiment, the second liquid ammonia spray oil beam 17 ejected from the injection hole 61 belonging to the two second injection hole groups 620 diffuses in the region within 5 mm of the hot surface of the heating element 41.

[0065] According to an embodiment of the present disclosure, as Figure 1 shown, the axis of the glow plug 4 coincides with the axis of the combustion chamber 3, and the axis of the liquid ammonia injector 6 is inclined with respect to the axis of the glow plug 4, such that the liquid ammonia spray ejected from the first injection hole group 610 directly impacts on the hot surface of the heating element 41.

[0066] According to an embodiment of the present disclosure, the angle between the axis of the liquid ammonia injector 6 and the axis of the glow plug 4 is approximately 10° to 20°.

[0067] According to an embodiment of the present disclosure, the axis of the spark plug 7 is inclined with respect to the axis of the glow plug 4 to ignite the liquid ammonia spray around the heating element 41.

[0068] According to an embodiment of the present disclosure, the angle between the axis of the spark plug 7 and the axis of the glow plug 4 is approximately 10° to 20°.

[0069] According to an embodiment of the present disclosure, as Figure 1 and Figure 2 shown, the pure ammonia engine system further includes a liquid ammonia supply mechanism 100, a liquid ammonia boosting device 11, and a liquid ammonia common rail 12. The liquid ammonia supply mechanism 100 is configured to supply liquid ammonia. The liquid ammonia boosting device 11 is connected to the liquid ammonia supply mechanism 100, and the liquid ammonia boosting device 11 is configured to boost the pressure of the liquid ammonia. The liquid ammonia common rail 12 is connected between the liquid ammonia boosting device 11 and the liquid ammonia injector 6, and the liquid ammonia common rail 12 is configured to regulate the pressure of the liquid ammonia ejected from the plurality of injection hole groups 600.

[0070] According to an embodiment of the present disclosure, the liquid ammonia supply mechanism 100 includes an ammonia gas source 8, an ammonia gas liquefaction device 9, and an instantaneous fuel consumption meter 10. The ammonia gas source 8 is configured to provide ammonia gas. The ammonia gas liquefaction device 9 is connected to the ammonia gas source 8 and is configured to liquefy the ammonia gas to obtain liquid ammonia. The instantaneous fuel consumption meter 10 is connected to the ammonia gas liquefaction device 9 and is configured to monitor the injection amount and consumption of the liquid ammonia in real time, so as to optimize the combustion efficiency. By measuring the instantaneous consumption of the liquid ammonia, the combustion efficiency of the pure ammonia engine system under different operating conditions can be analyzed. Combining with the operating parameters of the pure ammonia engine system (such as the rotational speed value, intake air volume, etc.), the instantaneous fuel consumption meter 10 can provide data support for the controller 5 to adjust the injection strategy of the liquid ammonia, ensuring the stability and high efficiency of the combustion process in the combustion chamber 3.

[0071] According to an embodiment of the present disclosure, the controller 5 is electrically connected to the liquid ammonia booster device 11, the liquid ammonia common rail 12, the liquid ammonia injector 6, the glow plug 4, and the spark plug 7, so that the liquid ammonia common rail 12 can provide a stable liquid ammonia pressure and a more optimized injection time, ensuring that the liquid ammonia injector 6 can inject the liquid ammonia into the combustion chamber 3 in the form of a liquid ammonia spray beam with an accurate injection amount, reducing the unburned liquid ammonia in the combustion chamber 3 to meet the requirements of the pure ammonia engine system for liquid ammonia supply under different operating conditions and improving the overall thermal efficiency of the pure ammonia engine system.

[0072] Figure 4 It is a flowchart of a control method for a pure ammonia engine system according to an illustrative embodiment of the present disclosure.

[0073] According to an embodiment of another aspect of the present disclosure, as Figure 4 shown, a control method for a pure ammonia engine system is provided, which is applied to the above pure ammonia engine system. The control method includes the following steps S1 to step S2.

[0074] Step S1: Obtain the operating conditions of the pure ammonia engine system.

[0075] Step S2: The glow plug 4 adjusts the temperature of the hot surface of the heating element 41 in response to the operating conditions of the pure ammonia engine system, providing different temperature environments for the spark plug 7 to ignite the liquid ammonia spray inside the combustion chamber 3.

[0076] According to an embodiment of the present disclosure, in response to different operating conditions of the pure ammonia engine system, the controller 5 controls the hot surface of the heating element 41 to increase or decrease in temperature, providing different temperature environments for the spark plug 7 to ignite the liquid ammonia spray inside the combustion chamber 3, which can ensure that the pure ammonia engine system can stably ignite under all operating conditions.

[0077] According to an embodiment of the present disclosure, the levels of operating conditions are classified from low to high according to the output torque of the pure ammonia engine system as cold start condition, small load condition, medium load condition, and large load condition. The temperature inside the combustion chamber 3 increases with the increase of the output torque. When the pure ammonia engine system is in the cold start condition, the glow plug 4 is controlled to work at full load. As the pure ammonia engine system runs to the small load condition and medium load condition, the temperature of the hot surface is controlled to gradually decrease. As the pure ammonia engine system runs to the large load condition, the glow plug 4 is controlled to stop working.

[0078] According to an embodiment of the present disclosure, the controller 5 controls the temperature of the hot surface of the heating element 41 to decrease with the increase of the operating condition level. When the pure ammonia engine system is in the cold start condition, at this time, the thermodynamic conditions inside the combustion chamber 3 are poor, and it is difficult for liquid ammonia to achieve stable ignition. The controller 5 controls the hot surface of the heating element 41 to heat up, so that the area around the hot surface of the heating element 41 is a high-temperature area, thereby increasing the temperature inside the combustion chamber 3. The liquid ammonia spray ejected from the first spray hole group 610 impacts on the hot surface of the heating element 41, and the liquid ammonia sprays ejected from the two second spray hole groups 620 fill the surrounding of the heating element 41, and thus are ignited by the spark plug 7, solving the problem of slow combustion speed of liquid ammonia, enabling the liquid ammonia spray to burn stably after ignition, and fully ensuring the cold start performance of the pure ammonia engine system at this time.

[0079] According to an embodiment of the present disclosure, when the pure ammonia engine system is in the small load condition and medium load condition, at this time, the thermodynamic conditions inside the combustion chamber 3 are improved. The controller 5 controls the hot surface of the heating element 41 to cool down, which not only ensures the stable combustion of the liquid ammonia spray inside the combustion chamber 3, but also improves the energy utilization efficiency of the pure ammonia engine system.

[0080] According to an embodiment of the present disclosure, when the pure ammonia engine system is in the large load condition, at this time, the thermodynamic conditions inside the combustion chamber 3 have been improved to ensure the stable combustion of the liquid ammonia spray inside the combustion chamber 3. The controller 5 controls the glow plug 4 to stop working, improving the energy utilization efficiency of the pure ammonia engine system.

[0081] According to an embodiment of the present disclosure, when the pure ammonia engine system is in the cold start condition, the temperature of the hot surface is 300°C to 400°C. When the pure ammonia engine system runs to the small load condition and medium load condition, the temperature of the hot surface is 100°C to 200°C.

[0082] According to an embodiment of the present disclosure, when the pure ammonia engine system is in the cold start condition, the controller 5 controls the hot surface of the heating element 41 to heat up, and the temperature of the hot surface is preferably 300°C, and the cold start performance of the pure ammonia engine system is fully ensured at this time.

[0083] According to an embodiment of the present disclosure, when the pure ammonia engine system operates in a small load condition and a medium load condition, the thermodynamic conditions in the combustion chamber 3 are improved at this time, and the controller 5 controls the hot surface of the heating element 41 to cool down. The temperature of the hot surface is preferably 100 °C, which not only ensures the stable combustion of the liquid ammonia spray in the combustion chamber 3, but also improves the energy utilization efficiency of the pure ammonia engine system.

[0084] According to an embodiment of the present disclosure, the controller 5 can adjust the temperature of the hot surface of the heating element 41 of the glow plug 4 in real time according to different operating conditions (loads) of the pure ammonia engine system, and improves the overall energy utilization efficiency of the pure ammonia engine system on the premise of ensuring the stable ignition of the liquid ammonia spray.

[0085] According to an embodiment of the present disclosure, according to the rotational speed value of the rotational speed sensor connected to the crankshaft of the pure ammonia engine system and the displacement of the accelerator pedal connected to the pure ammonia engine system, the output torque of the pure ammonia engine system is determined, thereby determining the operating condition of the pure ammonia engine system.

[0086] According to an embodiment of the present disclosure, according to the rotational speed value of the rotational speed sensor connected to the crankshaft of the pure ammonia engine system and the displacement of the accelerator pedal connected to the pure ammonia engine system, the displacement of the accelerator pedal of the pure ammonia engine system can be obtained by the accelerator sensor installed on the accelerator pedal, the output torque of the pure ammonia engine system is determined, thereby determining the operating condition of the pure ammonia engine system. Among them, according to the output torque from low to high, the operating conditions of the pure ammonia engine system are divided into a cold start condition, a small load condition, a medium load condition, and a large load condition in ascending order of level.

[0087] According to an embodiment of the present disclosure, the first start of the pure ammonia engine system in a low temperature environment (temperature not greater than 5 °C) is a cold start condition, the load rate of the pure ammonia engine system is less than 25% is a small load condition, the load rate of the pure ammonia engine system is between 25% and 85% is a medium load condition, the load rate of the pure ammonia engine system is greater than 85% is a large load condition, and the load rate is the ratio of the current output torque to the maximum torque.

[0088] Those skilled in the art can understand that the features described in the various embodiments and / or claims of the present disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in the present disclosure. In particular, without departing from the spirit and teachings of the present disclosure, the features described in the various embodiments and / or claims of the present disclosure can be combined and / or combined in various ways. All such combinations and / or combinations fall within the scope of the present disclosure.

[0089] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "rear", "left", "right", etc., are only references to the directions in the accompanying drawings and are not used to limit the protection scope of the present disclosure. Throughout the drawings, the same elements are denoted by the same or similar reference numerals. When it may cause confusion in the understanding of the present disclosure, the conventional structures or configurations will be omitted, and the shapes and sizes of the components in the drawings do not reflect the actual sizes and proportions, but only illustrate the content of the embodiments of the present disclosure.

[0090] Unless otherwise known to the contrary, the numerical parameters in this specification and the appended claims are approximate values and can be changed according to the required characteristics obtained through the content of the present disclosure. Specifically, all the numbers representing the contents of components, reaction conditions, etc. used in the specification and claims should be understood to be modified by the term "about" in all cases. Generally, the meaning it expresses is that it includes a change of ±10% in some embodiments, a change of ±5% in some embodiments, a change of ±1% in some embodiments, and a change of ±0.5% in some embodiments for a specific quantity.

[0091] The ordinal terms such as "first", "second", "third", etc. used in the specification and claims are used to modify the corresponding elements. They do not themselves mean that the elements have any ordinal numbers, nor do they represent the order of one element and another element or the order in the manufacturing method. The use of these ordinal numbers is only to clearly distinguish an element with a certain name from another element with the same name.

[0092] In addition, unless specifically described or steps that must occur in sequence, the order of the above steps is not limited to those listed above and can be changed or rearranged according to the required design. And the above embodiments can be used in combination with each other or combined with other embodiments based on considerations of design and reliability, that is, the technical features in different embodiments can be freely combined to form more embodiments.

[0093] The embodiments of the present disclosure have been described above. However, these embodiments are only for illustrative purposes and not for limiting the scope of the present disclosure. Although the embodiments have been described separately above, this does not mean that the measures in each embodiment cannot be used advantageously in combination. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art can make various substitutions and modifications, and these substitutions and modifications should all fall within the scope of the present disclosure.

Claims

1. A pure ammonia engine system, wherein, Comprising: Cylinder block; Cylinder head, disposed above the cylinder block, a combustion chamber being formed between the cylinder head and the cylinder block; Glow plug, including a heating element extending into the interior of the combustion chamber at the center of the cylinder head; Controller, configured to regulate the temperature of the hot surface of the heating element based on the operating conditions of the pure ammonia engine system; Liquid ammonia injector, inserted into the combustion chamber from the cylinder head and located on one side of the glow plug; Spark plug, inserted into the combustion chamber from the cylinder head and located on the other side of the glow plug radially opposite to the liquid ammonia injector; Wherein, at one end of the liquid ammonia injector extending into the interior of the combustion chamber, a plurality of spray hole groups are provided on one side facing the heating element, such that a part of the liquid ammonia spray ejected by the liquid ammonia injector fills the periphery of the heating element to be ignited by the spark plug.

2. The pure ammonia engine system according to claim 1, wherein, The plurality of spray hole groups include: First spray hole group, provided facing the heating element, such that the liquid ammonia spray ejected by the first spray hole group impacts on the hot surface of the heating element to accelerate the fragmentation and evaporation of the liquid ammonia spray ejected by the first spray hole group and mix with the air in the combustion chamber to form a combustible mixture, thereby being ignited by the spark plug; Two second spray hole groups, symmetrically distributed on both sides of the first spray hole group perpendicular to the plane where the axis direction of the liquid ammonia injector is located, such that the liquid ammonia sprays ejected by the two second spray hole groups fill the periphery of the heating element.

3. The pure ammonia engine system according to claim 2, wherein, The first spray hole group and each of the second spray hole groups include: Two spray holes, arranged at intervals along the axis of the liquid ammonia injector.

4. The pure ammonia engine system according to claim 2, wherein, The axis of the glow plug coincides with the axis of the combustion chamber, and the axis of the liquid ammonia injector is inclined with respect to the axis of the glow plug, such that the liquid ammonia spray ejected by the first spray hole group directly impacts on the hot surface of the heating element.

5. The pure ammonia engine system according to claim 4, wherein, The axis of the spark plug is inclined with respect to the axis of the glow plug to ignite the liquid ammonia spray around the heating element.

6. The pure ammonia engine system according to claim 1, wherein, Further comprising: Liquid ammonia supply mechanism, configured to supply liquid ammonia; Liquid ammonia booster, connected to the liquid ammonia supply mechanism, the liquid ammonia booster being configured to boost the pressure of the liquid ammonia; Liquid ammonia common rail, connected between the liquid ammonia booster and the liquid ammonia injector, the liquid ammonia common rail being configured to regulate the pressure of the liquid ammonia ejected by the plurality of spray hole groups.

7. A control method for a pure ammonia engine system, wherein, Applied to the pure ammonia engine system according to any one of claims 1-6 above, the control method includes: Obtaining the operating conditions of the pure ammonia engine system; The glow plug responds to the operating conditions of the pure ammonia engine system and adjusts the temperature of the hot surface of the heating element to provide different temperature environments for the spark plug to ignite the liquid ammonia spray inside the combustion chamber.

8. The control method according to claim 7, wherein, The operating conditions are divided into a cold start condition, a small load condition, a medium load condition, and a large load condition according to the output torque of the pure ammonia engine system from low to high, and the temperature inside the combustion chamber increases with the increase of the output torque; When the pure ammonia engine system is in the cold start condition, control the glow plug to operate at full load; When the pure ammonia engine system operates to the small load condition and the medium load condition, control the temperature of the hot surface to gradually decrease; When the pure ammonia engine system operates to the large load condition, control the glow plug to stop working.

9. The control method according to claim 8, wherein, When the pure ammonia engine system is in the cold start condition, the temperature of the hot surface is 300°C to 400°C; When the pure ammonia engine system operates to the small load condition and the medium load condition, the temperature of the hot surface is 100°C to 200°C.

10. The control method according to claim 8, wherein, According to the rotational speed value of the rotational speed sensor connected to the crankshaft of the pure ammonia engine system and the displacement of the accelerator pedal connected to the pure ammonia engine system, determine the output torque of the pure ammonia engine system, so as to determine the operating condition of the pure ammonia engine system.

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